A system is provided in the present disclosure. The system may acquire a first set of echo signals and a second set of echo signals relating to a subject. The first and the second set may be generated by using an MR scanner to execute a first acquisition and a second acquisition on the subject, respectively. The first acquisition may include at least a first repetition and a second repetition with different repetition times. Each of the first and second repetitions may have a first flip angle. The second acquisition may include at least a third repetition and a fourth repetition with different repetition times. Each of the third repetition and the fourth repetition may have a second flip angle different from the first flip angle. The system may also perform a measurement on the subject based on at least one of the first set or the second set.

The present disclosure relates to a method and a magnetic resonance imaging device for two-dimensional (2D) magnetic resonance (MR) imaging of a subject. The disclosure further relates to a corresponding computer program and a corresponding computer-readable storage medium. In one exemplary method, a k-space dataset of the subject is acquired using a simultaneous multi-slice technique. Therein, a blipped phase-encoding gradient is applied in a pseudo-random manner to achieve an incoherent undersampling at least in a k-space direction perpendicular to a slice select direction. A compressed sensing reconstruction is then performed based on the acquired k-space dataset to generate an MR image of the subject.

A method for correcting magnetic resonance (MR) object movements includes performing a recording of an MR object with multiple echo trains. k-space data pertaining to an echo train regarded as impaired by an MR object movement is corrected by linking the k-space data to corresponding k-space data reconstructed from k-space data of other echo trains by a PPA method.

A method and apparatuses are provided to perform chemical species separation in magnetic resonance (MR) imaging (MRI). At least three MR images corresponding respectively to different echo times are obtained and represent signals from multiple chemical species including a first species and a second species in a tissue. A plurality of dual-echo pairs is selected from the at least three MR images. For each pair, a set of dual-echo separated images including a B0 field map, a first image for the first species, and a second image for the second species is estimated. An initial set of combined images including at least one of: an initial combined B0 field map, first, and second image is generated by combining at least one of: two or more of the B0 field maps, two or more of the first images, and two or more of the second images.

A new method is developed for ultrafast, high-resolution magnetic resonance spectroscopic imaging (MRSI) using learned spectral features. The method uses Free Induction Decay (FID) based ultrashort-TE and short-TR acquisition without any solvent suppression pulses to generate the desired spatiospectral encodings. The spectral features for the desired molecules are learned from specifically designed training data by taking into account the resonance structure of each compound generated by quantum mechanical simulations. A union-of-subspaces model that incorporates the learned spectral features is used to effectively separate the unsuppressed water/lipid signals, the metabolite signals, and the macromolecule signals. The unsuppressed water spectroscopic signals in the data can be used for various purposes, e.g., removing the need of additional auxiliary scans for calibration, and for generating high quality quantitative tissue susceptiability mapping etc. Simultaneous spatiospectral reconstructions of water, lipids, metabolite and macromolecule can be obtained using a single .sup.1H-MRSI scan.

A Magnetic Resonance Imaging (MM) system, called ULTRA (Unlimited Trains of Radio Acquisitions), can operate with essentially no magnetic gradient reversals. Each of a multitude of small receiver coils arranged in a 3D array around the imaging volume simultaneously acquires MR signal from the entire volume. This greatly increases the rate of MR signal acquisition and allows a full MR image to be reconstructed in as little as 1 millisecond. Both electrical and audible noise is greatly reduced.

A method and apparatus for determining spatial distribution of a complex radio frequency (RF) of both transmit field and receive sensitivity a magnetic resonance imaging (MRI) system. The method includes estimation of the absolute phase of transmit field using a reference transmit coil or array coils with minimal absolute phase. The method and apparatus include estimation of complex receive sensitivity of a transceiver coil using the complex transmit field of the transceiver coil or array coils.

The embodiments of the present application disclose a method and an apparatus for determining flow rates of components of multiphase fluid. The method comprises: performing a first magnetization treatment and a second magnetization treatment on multiphase fluid in a pipeline in a target oil and gas well, respectively, to obtain first magnetized multiphase fluid and second magnetized multiphase fluid; determining a first echo train signal set and a second echo train signal set corresponding to the first magnetized multiphase fluid and the second magnetized multiphase fluid, respectively; determining contents of an oil phase component, a water phase component, and a gas phase component of the multiphase fluid at a specified horizon position, and determining a flow velocity of the multiphase fluid at the specified horizon position; and determining flow rates of the oil phase component, the water phase component and the gas phase component in the multiphase fluid. The technical solutions provided by the embodiments of the present application can improve the accuracy of the determined flow rate of each component of the multiphase fluid.

Methods and apparatus for operating a low-field magnetic resonance imaging (MRI) system to perform diffusion weighted imaging, the low-field MRI system including a plurality of magnetics components including a B.sub.0 magnet configured to produce a low-field main magnetic field B.sub.0, at least one gradient coil configured to, when operated, provide spatial encoding of emitted magnetic resonance signals, and at least one radio frequency (RF) component configured to acquire, when operated, the emitted magnetic resonance signals. The method comprises controlling one or more of the plurality of magnetics components in accordance with at least one pulse sequence having a diffusion-weighted gradient encoding period followed by multiple echo periods during which magnetic resonance signals are produced and detected, wherein at least two of the multiple echo periods correspond to respective encoded echoes having an opposite gradient polarity.

A magnetic resonance imaging MRI method and apparatus for lengthening the usable echo-train duration and reducing the power deposition for imaging is provided. The method explicitly considers the t1 and t2 relaxation times for the tissues of interest, and permits the desired image contrast to be incorporated into the tissue signal evolutions corresponding to the long echo train. The method provides a means to shorten image acquisition times and/or increase spatial resolution for widely-used spin-echo train magnetic resonance techniques, and enables high-field imaging within the safety guidelines established by the Food and Drug Administration for power deposition in human MRI.